<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <script>
        const obj = {
            name: 'pink老师',
            age: 20
        };
        const o = obj;
        o.age = 18;
        console.log(obj);//{name: 'pink老师', age: 18}
        console.log(o);//{name: 'pink老师', age: 18}
        //obj.age也会被改变
    </script>
</body>

</html>